When the elevator doors open, Thomas can only remember his first name. But he is not alone. He is surrounded by boys who welcome him to the Glade - a walled camp at the center of a bizarre and terrifying stone labyrinth. Like Thomas, the Gladers do not know why or how they ended up there or what has happened to the world outside. All they know is that every morning, when the walls slide back, they will risk everything, even the Grievers, part machine, part animal, that patrol the corridors to find out what has happened.